Answer;
= 5.102 m
Explanation;
The total energy, i.e. sum of kinetic and potential energy, is constant.
That is; E = KE + PE
Initially, PE = 0 and KE = 1/2 mv^2
At maximum height, velocity=0, thus, KE = 0 and PE = mgh
Since, total energy is constant (KE converts to PE when the ball is rising).
Therefore, KE = PE
or, 1/2 mv^2 = mgh
or, h = v^2 /2g
= 10^2 / (2x9.8)
= 5.102 m